This article describes a method for analyzing 1,2-ethylene dibromide (EDB) and 1,2-dibromo-3-chloropropane (DBCP) in water using the Agilent 6890 series gas chromatograph and Agilent 6890 micro-electron capture detector. The method follows EPA Method 504, using microextraction to extract the analytes from the sample, and then analyzing the extract by dual-column gas chromatography with dual micro-electron capture detectors (Agilent 6890 micro-ECDs). The micro-ECD provides significantly better stability, sensitivity, and linearity than the classical ECD. The relative standard deviation (% RSD) for the entire method is less than 7% over a concentration range greater than two orders of magnitude, with method detection limits of 0.003 mmmmg/L or lower.
The document describes a method for analyzing volatile pesticides ethylene dibromide (EDB) and 1,2-dibromo-3-chloropropane (DBCP) in drinking water. The procedure involves micro-extraction with hexane followed by dual-column gas chromatography using an Agilent 6890 Series instrument equipped with dual micro-ECDs.
Results indicate that the micro-ECD offers significantly improved stability, sensitivity, and linearity compared to classical ECDs. The method achieved detection limits of 0.003 µg/L or lower for both analytes, meeting and exceeding EPA Method 504 requirements with excellent precision and accuracy over a three-month operational period.
| Detection Limit (EDB) | 0.003 µg/L or lower |
|---|---|
| Detection Limit (DBCP) | 0.003 µg/L or lower |
| Relative Standard Deviation | < 7% |
| Linearity Range | 0.010 to 1.14 µg/L |
| Correlation Coefficient | > 0.999 |
The method detection limits were 0.002 µg/L for EDB and 0.003 µg/L for DBCP.
The system remained stable for a long period of 3 months with little or no maintenance required except for routine septum and liner changes.
No, the optimized conditions clearly separate EDB from significant levels of dibromochloromethane (DBCM) and other interferences.